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Marketable and Other Securities - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Marketable Securities [Line Items]
Sales proceeds from investments classified as available-for-sale and sold prior to maturity	$ 1,900	$ 4,500	$ 4,300
Lyft, Inc. | Interest Income and Other Non-Operating Income
Marketable Securities [Line Items]
Unrealized gain (loss) on securities			$ 142

X

- Definition

Amount of unrealized gain (loss) recognized in income from asset (liability) measured at fair value on recurring basis using unobservable input (level 3) and still held.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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- Definition

Amount of cash inflow from sale of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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